Mental acuity is a term used to describe a person's mental sharpness or intelligence. It is often associated with the ability to think quickly and accurately, as well as the capacity to remember and recall information. The crossword solutions for the term mental acuity are 'BRAINS' (6 letters), 'WITS' (4 letters), and 'WIT' (3 letters). All three words refer to a person's mental sharpness and intelligence, with 'BRAINS' being the most comprehensive term, 'WITS' referring to a person's quick-thinking abilities, and 'WIT' referring to a person's cleverness and humor.